Hot patching is a new type of pavement repair process. Simply put, "hot patching technology" uses a specially designed heating device to provide powerful heat. While maintaining the properties of the asphalt mixture, it quickly and safely heats the old asphalt surface to mixing and compaction temperatures. Through recycling and other technical measures, the damaged pavement is restored to or near the technical specifications of the original pavement. The advantages of this process include year-round operation, ensuring timely treatment of defects; hot joints between the new and old pavements, improving repair quality; mechanized operations reduce worker intensity; and the recycled asphalt mixture reduces maintenance costs and environmental pollution.
On-site hot patching of damaged pavement requires equipment such as a comprehensive maintenance vehicle, pavement heating plates, power picks, and cutting machines. After marking, the road surface is cut, and the surface and base mixes are removed before the base is treated. The recyclable surface material removed is broken into small pieces and filled into the potholes. The old material around and within the potholes is then heated using a heating plate (layered heating is possible). Finally, emulsified asphalt and an appropriate amount of new material are added, mixed, leveled, and compacted using a roller.

In the hot patching process, each step is performed by a separate machine, and each machine operates independently without interfering with each other, allowing for a streamlined operation. When the pavement defect is large, several independent heating plates can be combined for centralized heating. Furthermore, when the pavement defect is concentrated, certain steps, such as removing the surface and base, and spreading the mixture, can be performed semi-manually.
When performing hot patching operations, before heating pavement defects such as potholes, cracks, oil pockets, and rutting, the old surface material should be inspected to determine its recyclability. For old surface material that cannot be recycled, dust, loose particles, accumulated water, and other debris should be cleaned from the affected area.
Before heating the affected area, open the valves of all liquefied gas tanks and then the valves of all pipelines. To ensure that the working surface does not deteriorate, adjust the heating time (intermittent heating and continuous heating modes are available). Generally, 5 to 10 minutes is sufficient. The required stable temperature for construction is generally 140 to 170 degrees Celsius. The specific heating time can be determined through heating experiments based on the season and specific environmental conditions.
After removing the heating plate, immediately loosen the regenerated area to be repaired. Use a tooth rake and the back edge of a push plate to create a square around the affected area. This square should be at least 15 cm from the edge of the affected area and at least 10 cm from the outer edge of the heated area. The loosening depth will vary depending on the softening depth of the heating process. Some of the renewable asphalt materials on the original road surface may have been oxidized. Depending on the degree of oxidation of the recycled asphalt materials, spray a small amount of asphalt activator or new materials evenly after loosening them, mix them evenly, and level them. At the same time, push the asphalt materials scattered on the edges to make them flat, and finally compact and clean the site.